From our most favorite web-site, The Astronomy Picture of the Day:
Gliese 581 itself is not a sun-like star, though.
Classified as a
dwarf, the star is much smaller and colder than the Sun.
Still, the smallest planet known to orbit the star is estimated to
be five times as massive as Earth with about 1.5 times Earth’s
orbits once every 13 days, about 14 times closer
to its parent star than the Earth-Sun distance.
The close-in orbit around the cool star implies a mean surface
temperature of between 0 and 40 degrees C – a range over which water
would be liquid – and places the
the red dwarf’s
Are they looking at us while we are looking at them?